This application claims priority of European Patent Application No. 99302632.7, which was filed on Apr. 1, 1999.
The present invention relates to an RF receiver on a single integrated circuit chip, and particularly but not exclusively to such a receiver for use in the base station of a mobile communications system.
The analogue part of a mobile communications base station comprises radio frequency (RF) and IF circuitry. The RF circuitry is currently realised using discrete electronic components. In the interests of minimising circuit size and reducing costs, there is presently a drive toward the implementation of RF circuitry on integrated circuits (ICs).
The system architecture and RF IC requirements for different types of base station are significantly different, and this has led to the provision of integrated circuits implementing the RF circuitry for the different types of base station which can be used exclusively in the different types of applications.
For example, a base station for a macro-cellular mobile communications system requires a diversity channel, but may not necessarily require a low noise amplifier in the receiver channel. For a micro-cellular mobile communications system, a low noise amplifier and a diversity channel are usually required. For a pico-cellular system, neither a low noise amplifier nor a diversity channel is usually required.
Designing of RF IC receivers for all possible base station classes is thus costly and time consuming.
It is therefore an object of the present invention to provide an improved RF IC receiver.
According to the present invention there is provided an RF integrated circuit receiver structure comprising: a receiver channel; a selectable amplification stage associated with the receiver channel; and a selectable diversity channel associated with the receiver channel.
Thus there is proposed a general purpose, modular, radio frequency integrated circuit receiver architecture, which enables the system architecture to be configured differently around a single RF IC, to realise the functionality required for different base station applications.
For example, the amplification stage may be not selected, and the diversity channel may be selected, when the receiver channel is used in a base station of a macro-cellular mobile communications system.
In a further example the amplification stage may be selected and the diversity channel may be selected when the receiver channel is for use in a base station of a micro-cellular mobile communications system.
In a further example the amplification stage may not be selected and the diversity channel may not be selected when the receiver channel is for use in a base station of a pico-cellular mobile communications system.
The amplification stage is preferably a low noise amplifier.
The receiver channel may include a driver amplifier, a mixer, and an IF amplifier.
The elements of the receiver channel may be interconnected off-chip in accordance with the application of the receiver channel.
The diversity channel may comprise a driver amplifier, a mixer and an IF amplifier.
The elements of the diversity channel may be interconnected off-chip in accordance with the application of the receiver channel.
The invention will now be described by way of non-limiting example with reference to the attached drawings, in which: